Pen cap



FIG. 1 is a front view of the pen cap;

FIG. 2 is a rear view of the pen cap;

FIG. 3 is a side view of the pen cap, from the left of FIG. 1;

FIG. 4 is a side view of the pen cap, from the right of FIG. 1;

FIG. 5 is a perspective view of the pen cap;

FIG. 6 is a top view of the pen cap; and,

FIG. 7 is a bottom view of the pen cap. 

The ornamental design for a pen cap, as shown and described. 